The growth characteristics of vegetation in the Karst regions of Guizhou from 1981 to 2012

Guizhou province is located in the center area of Karst region, its ecological environment has been changed by biological process significantly. It is noted that the plants play an important role in the terrestrial ecosystem as the producer of the biosphere. Therefore, the updated Global Inventory Modeling and Mapping Studies (GIMMS) third generation Normalized Difference Vegetation Index (NDVI) dataset by using global satellite Advanced Very High Resolution Radiometer (AVHRR) was used to investigate the changes of vegetation in the Guizhou Province from 1982 to 2011. The results demonstrated that the overall NDVI increased from 1982 to 2011 with an average rate of 0.002 1 per year (P<0.001). However, there still were two turning points (TP) in 1985 and 1993, respectively. There are large variations between the NDVI trend and TPs in the whole area and in different vegetation types. From the spatial distribution of vegetation growth in Guizhou, the rate of vegetation increased in southeastern was superior to northwestern obviously. One reason was global warming, and meanwhile the vegetation change consisitent with the spatial distribution of precipitation. In addition, the impact of human activities on the changes of vegetation should be paid more attentions.